Tretinoin is a retinoid, and the Renova label calls it an endogenous retinoid metabolite of Vitamin A. Its labels describe uses for acne vulgaris (Retin-A) and for fine facial wrinkles (Renova 0.02%). How it works is only partly described: the Retin-A prescribing information says the exact mode of action of tretinoin is unknown.
What tretinoin is
The Renova (tretinoin cream) 0.02% label says tretinoin is also referred to as all-trans-retinoic acid and has a molecular weight of 300.44. The same label says tretinoin binds to intracellular receptors in the cytosol and nucleus.
Tretinoin creams are made in different ways. The table shows two label examples. Each row describes the product on that label only.
| Question | What the source says |
|---|---|
| What does the Retin-A cream label list? | Retin-A (tretinoin) Cream contains tretinoin in one of three strengths, 0.1%, 0.05%, or 0.025% by weight, in a hydrophilic cream vehicle (Retin-A label, updated May 2024). |
| What does the Tretinoin Cream, USP (Emollient) 0.05% label list? | Tretinoin at a concentration of 0.05% w/w in a water-in-oil emulsion formulation (label, updated August 2012). |
How labels describe the way it works
The Retin-A label uses careful wording. It says that although the exact mode of action of tretinoin is unknown, current evidence suggests that topical tretinoin decreases cohesiveness of follicular epithelial cells with decreased microcomedo formation. It also says tretinoin stimulates mitotic activity and increased turnover of follicular epithelial cells, causing extrusion of the comedones.
The Renova label is more cautious still. It says it has not been established whether the clinical effects of tretinoin are mediated through activation of retinoic acid receptors, other mechanisms such as irritation, or both. Both labels state plainly what is unknown or not established.
The skin conditions behind these statements
Acne: MedlinePlus describes acne as a common skin disease that causes pimples, which form when hair follicles under your skin clog up. The National Institute of Arthritis and Musculoskeletal and Skin Diseases says people of all races and ages get acne, but it is most common in teens and young adults.
Sun-related skin changes: MedlinePlus says sunlight is a major cause of skin aging. Its protection list is staying out of the sun when it is strongest, using sunscreen with an SPF of 15 or higher, wearing protective clothing, and avoiding sunlamps and tanning beds. The abstract of a Cochrane review says photodamage describes skin changes such as fine and coarse wrinkles, roughness, freckles and pigmentation changes that occur as a result of prolonged exposure to the sun.
MedlinePlus also says many products claim to revitalize aging skin or reduce wrinkles, but the Food and Drug Administration has approved only a few for sun-damaged or aging skin.
What this does not tell you
The Retin-A statements above are about follicular cells and comedones. None of the statements here explains how tretinoin acts on fine wrinkles, and the Renova label says it has not been established whether effects come from receptor activation, irritation or both.
These sources also do not say how any one person's skin will respond, or which strength suits a person. A licensed provider decides that.
Finally, each label describes the product it names. The FDA page Compounding and the FDA: Questions and Answers says compounded drugs are not FDA-approved, meaning FDA does not verify the safety, effectiveness or quality of compounded drugs before they are marketed. A label statement about a named product should not be read as describing a compounded cream.